Jump to content
SAU Community

Vct Help!

JonTurpening
 Share

Recommended Posts

JonTurpening Enthusiast

JonTurpening

Posted
Posted

First off I'm not sure if my VCT is working. I have power going to the valve and I do hear a "click" coming from it when the throttle plate is opened.

The thing is it makes no difference whether I plug the valve in or leave it unplugged. I've had it to the dyno 3 different times and the last time I made sure it was "clicking". The results were the same plugged in or not!

Can someone tell me how I can test it to make sure it's working? I know I have 12v going to one side and like I said above I can hear and feel a "click" from it when I open the throttle plate and once again when I close it.

Does it work off oil pressure? Can the passages get clogged? The car is making good power (379.5rwhp) but there is not 1hp difference plugged up or not!

Thanks again guys for all your help!!

Link to comment
https://www.sau.com.au/forums/topic/225581-vct-help/
Share on other sites
QWK32 Veteran

QWK32

Posted
Posted (edited)

you wont notice a difference in overall power. but there will be a difference in the low down power. so if it is working properly you will have slightly more power at say 3000rpm with it plugged than you would if you unplug it.

best way to look at this is to do a dyno run with it plugged in and one with it unplugged. then overlap the printouts of the two runs to see where it slight gain is.

Edited by QWK32
Link to comment
https://www.sau.com.au/forums/topic/225581-vct-help/#findComment-3972956
Share on other sites
JonTurpening Enthusiast

JonTurpening

Posted
  • Author
Posted (edited)

I have. That's just it. There is no difference in power at that rpm range with it plugged in or not.

Here are two dyno plots the only difference in them is that we added about 1.5-2psi of boost and one had the valve plugged in and the other did not. There is no difference in the lower rpm range at all. (The 379 was plugged in and the 363 was not. we did a run at the same boost level with it plugged in and it was the same I just didn't get a print out of it.)

you wont notice a difference in overall power. but there will be a difference in the low down power. so if it is working properly you will have slightly more power at say 3000rpm with it plugged than you would if you unplug it.

best way to look at this is to do a dyno run with it plugged in and one with it unplugged. then overlap the printouts of the two runs to see where it slight gain is.

post-42695-1214449694_thumb.jpg

post-42695-1214449936_thumb.jpg

Edited by JonTurpening
Link to comment
https://www.sau.com.au/forums/topic/225581-vct-help/#findComment-3973054
Share on other sites
blind_elk Grand Master

blind_elk

Posted
Posted

Not made easy by having different horizontal scales. If you look really closely, there are differences between the "with VCT" and "without VCT" graphs.

But you made two changes - boost and VCT. You need to run back-to-back, with only 1 change, namely VCT on / off. When you start changing other variables, you can't possibly tell which change had the effect. And running them a month apart could also interfere with the results - different weather, dyno recalibrated, different ramp rate, who knows.

Link to comment
https://www.sau.com.au/forums/topic/225581-vct-help/#findComment-3973296
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • jtha7
      Replacing turbo water line - any recommendations or advice?

      By jtha7 · Posted

      Hi all, Restoring r33 series 1 rb25det. All the heater hoses were on their way out, have replaced them and put it all back together. After testing I noticed a small leak from behind the head on the actual metal water line to the turbo when cars warm. I tried running a longer hose over it but it kept leaking...   I am about to take the (stock) manifold off again😔 to change the water line does any one have any lines they recommend? I was looking at Aeroflow Turbo Oil & Water Line Set but not sure what everyone else recommends. Car is completely stock but want to upgrade turbo eventually. it looks like ill have to disconnect a lot just to replace these lines so if there's anything else recommended to do please let me know. Thank you in advance!
    • MBS206
      RB20DE NEO smallbox clutch.

      By MBS206 · Posted

      From memory, on the R33 GTSt at least, while everyone says "It's not adjustable", I found when I changed clutches in mine, it just needed a small adjustment on the rod length. But be very wary here, as you could end up trying to push the pushrod in the master too far, or blowing out the slave.   Most likely though, if the master/slave isn't bypassing internally or leaking out, then the throw out is the wrong height compared to the fingers on the clutch, so when it moves to disengage the clutch, it isn't 100% disengaged. You can check part of this out too by jacking the car up, having the engine running, put your foot on the clutch and try to engage 1st gear. If it goes in pretty easy (Compared to the ground) and/or the wheels start turning a fair bit and it takes a bit too much brake pedal to bring them back to a stop, this is likely the issue.  I'm not sure if you can adjust the height of the forks etc in these though, it's been that long since I've touched any RB gearbox.
    • MBS206
      Lock up the old for sale / wtb threads.

      By MBS206 · Posted

      That's all good, I thought I was missing some interesting feature! Maybe @PranK can double check if that is something that is meant to be operating or not.
    • Kapr
      RB20DE NEO smallbox clutch.

      By Kapr · Posted

      I hope that is not something that bad. From what i remember he said that only first gear is "hard" to get in and that he has couple of ideas what to try next but idk 😕  hope it is not gearbox out. I will let you know.
    • GTSBoy
      RB20DE NEO smallbox clutch.

      By GTSBoy · Posted

      If it's not the hydraulics, it is probably gearbox back out. Usually as per @Duncan's post, or otherwise associated with not getting the throwout fork positioned correctly. All the way up to catastrophically bolting shit back together without it being aligned properly and wrecking the clutch/input shaft/flywheel/something else.
×
×
  • Create New...